THE World Health Organisation (WHO) is currently working on developing alternative or second-line treatments, or combination therapies of existing Neglected Tropical Diseases (NTDs) medicines, following indications that some NTDs were developing resistance to the different antimicrobials used to treat Neglected Tropical Diseases (NTDs), a new report has announced.
By Michael Gwarisa
The emergence of treatment failure has already been observed in kinetoplastids and in the causative organisms of leprosy among the bacterial NTDs. This development could hamper efforts in countries such as Zimbabwe where Leprosy has resurfaced and has reportedly been on the increase since 2020.
According to the 2023 Global report on neglected tropical diseases, this development whereby resistance to NTD treatment is being recorded threatens to derail progress towards the road map targets.
Various levels of antimicrobial resistance have also been reported in relation to the medicines used to treat human African trypanosomiasis (melarsoprol), all forms of leishmaniasis (pentavalent antimonials) and leprosy (dapsone, rifampicin, fluoroquinolones). Most anthelminthic medicines used in NTD programmes are also used to treat parasitic infections in animal populations: although resistance has been documented in animals, this is not the case yet in humans, but the risk cannot be underestimated.
The development and spread of resistance by pathogens to the different antimicrobials used to treat NTDs threatens to derail progress towards the road map targets. The emergence of treatment failure is a phenomenon that has already been observed in kinetoplastids and in the causative organisms of leprosy among the bacterial NTDs. It is therefore of paramount importance that drug efficacy is closely monitored throughout the NTD spectrum, and that surveillance mechanisms to monitor current and emerging resistance are systematically and thoroughly instituted in NTD interventions,” said the Report.
WHO has started supporting action and networks to monitor the efficacy of treatments for NTDs, and is committed to reinforcing collaboration with relevant sectors and stakeholders. This includes includes the causative agents of eumycetoma in the WHO list of high-priority fungal pathogens for research, development and public health action, including antimicrobial resistance (58), and more than 10 national schistosomiasis and STH programmes that have been distributing anthelminthics for more than six years are currently being monitored through a standardized protocol (59).
WHO has also published a guide for surveillance of antimicrobial resistance in leprosy; 2017 update (60) that helps countries in establishing or strengthening sentinel surveillance systems for determining primary and secondary resistance to rifampicin, dapsone and ofloxacin in treatment of leprosy; such systems are currently in place in over 50 countries.
“Work focusing on the development of alternative or second-line treatments, or combination therapies of existing medicines, as mentioned above in 3.1.4, is also contributing to ensure that interventions against specific NTDs remain efficacious.”
Meanwhile, in January 2021, WHO published its second road map for neglected tropical diseases (NTDs), with the goal of controlling, eliminating or eradicating many of these diseases by 2030. The road map was launched at a critical time, as the COVID-19 pandemic severely disrupted health systems, including supply chains for NTD medicines and health products, especially in low- and middle-income countries.
“These disruptions jeopardized support for prompt diagnosis, treatment and care, as well as for the provision of essential interventions such as vector control and veterinary public health, which are the mainstay of NTD programme activities. Other emergencies, such as conflict, flooding and earthquakes, further interrupted activities and compounded the NTD disease burden. Together, these challenges pose a significant risk to achieving the targets of the 2030 road map,” said Dr Tedros Adhanom Ghebreyesus, the Director-General World Health Organization.
Meanwhile, WHO and partners have been taking steps to mitigate the impact of COVID-19 on NTD services, which are gradually resuming.